. . . or put a magnet on that little ball and use a reed switch or hall effect device . . . How much water are we talking about here? A puddle under the water heater, a sump pump , a fish tank . . . ?
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. . . or put a magnet on that little ball and use a reed switch or hall effect device . . . How much water are we talking about here? A puddle under the water heater, a sump pump , a fish tank . . . ?
Last edited by Archangel; - 23rd October 2008 at 06:22.
If you do not believe in MAGIC, Consider how currency has value simply by printing it, and is then traded for real assets.
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Gold is the money of kings, silver is the money of gentlemen, barter is the money of peasants - but debt is the money of slaves
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There simply is no "Happy Spam" If you do it you will disappear from this forum.
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The Quantum touch sensors are very good at detecting water.
The human body is 9x% H2o.
These sensors can also detect through non metallic containers.
Norm
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I hope your ready for this one. I need 2 sensors. One to go in a skull and one to go in a coffin.Originally Posted by Joe S.
Now before anyone starts making assumptions about me let me explain that these are halloween props that have misters in. They are going outside and will run for a few hours but they use water pretty quick. Ive got valves etc all ready to top them up but i need to know when they go below a certain level. To make it simple im only having the 1 sensor. Instead of a high level sensor im just going to turn the valve on for a set amount of time.
I am i bit short on space so i was thinking of 2 wires dipped in the water. I like some of the other ideas. I never thought about doing them before. I do want to keep the cost down though. Things like "Quantum touch sensors" sound expensive.
One other thing i should mention. The PIC thats controlling it will be controlling a lot of other things aswell. I cant use any blocking commands. Ive never used ADCIN or POT before so im not sure if they are or not
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Use the wires and a 741 op amp.
When the water conducts across the wires the op amp triggers with the out put of the amp going high going to the pic. Or low if you wire the op amp the other way.
Dave
Always wear safety glasses while programming.
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Sounds good. Ive found an "LM741 SINGLE OP AMP DIL-8 (NSC) RC" in rapid. Ive not done much with opamps before but i found a page on google about the 741 so i can start learning now.
Thanx for your help
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The light/dark sensor on that page is pretty much what you want.
Basically the op amp will be a comparator. When the voltage difference between pins 2 and 3 is greater than 1.2 (if I remember) then pin 6 outputs. Single power supply is all that is needed with this setup.
Dave
Always wear safety glasses while programming.
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Ive only just got past the bit about boosted output. Some things are making sense but i think its gonna take a while to sink in properly.
Would i be right in saying an op amp is very similar (if not the same) as a MAX485 receiver? Now i think about it the MAX485 does have opamp type symbols in the datasheet
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You know I always make dead certain first, before I pull that trigger, on my de-soldering gun to remove MAX485s. Gotta be properly grounded, because they're very static sensitive.
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Maybe...I guess so...
The 484 is comparing a voltage difference.
Dave
Always wear safety glasses while programming.
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